Method of distilling coal



m 392$ msmw B. ZWILLHNGER METHOD OF DISTILLINGCOAL Filed July 14, 1922 5Sheets-Sheet 1 ATToRNEy I s Sheets-Sheet z INVENTOR M ATTORNEY Jan, 17,1928. I

B. ZWILLINGER METHOD OF DISTILLING COAL Filed July 14, 1922 n, W MN IJan, 117 1 928., flfiSfifiW B. ZWHLLENGER METHOD OF DISTILLING COALFiled July 14, 1922 '3 Sheets-Sheet 3 INVENTOR WM M BY ATTORHE PatentedJan. 17, 1928.

UNITED STATES PATENT OFFICE.

BEBNHARD ZWILLINGER, DECEASED, BY KLARA ZWILLINGER, ADMINISTRATBIZ, NEWYORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, T0 TAR & PETROLEUM PROCESSCOMPANY, OF CHICAGO, ILLINOIS, A. CORPORATION .OF ILLINOIS.

METHOD OF DISTILLING COAL.

Application filed July 14, 1922. Serial No. 574,988.

. In modern coke oven practice for the production of metallurgical cokeand byproducts great eiiorts have been made in the last decades tocarbonize large masses of coal and produce a uniformly carbonized cokewith as small an amount of heating gas as possible.

In spite of the progress which has been achieved in some directions, aconsiderable number of serious defects and disadvantages occur.

The coking of large masses in high, narrow, long chambers has first ofall led to considerable complication in the construction and a large'consumption of materials and labor.

In addition to these economic disadvantages the modern by-product ovenhas other drawbacks which limit its use to the carbonization of certainsorts of coals or mixtures of coals. Such coals for instance whichexpand during the degasifying process can only be used when mixed incertain proportions with a shrinking coal; otherwise the as wear andtear would be too large and the carbonization might even lead todestruction of the ovens.

Furthermore it is impossible to obtain all the valuable by-products inan unimpaired state, because the coal shrinks away from the heatingwalls whereby between the coke ends and walls irregular gaps andcrevices are formed which serve as paths for the travel of the gasesissuing from the coal. as The crude gases beingflsubjected to thecatalytic influence of hig y heated brick walls having an area of about720 square feet and of the incandescent coke ends, it can be readilyunderstood that a part of the byproducts must be destroyed. Theformation of these gaps and crevices between the heating walls and thecoke ends is the cause of other serious defects in addition to the lossof valuableby-products. Owing to the irregularity of the gaps it isimpossible to apply the heat in such a manner so as to roduce auniformly carbonized coke which is of so great im ortance in blastfurnace operationregard ess of what method of heating is applied tothese high ovens and of what nature the means are for controllingtheheat. The problem of heating the charge becomes still more complexand difiicult for the following reasons: a

The crude gases issuing from the charge as the carbonlzation progressestowards the center are considerably lower in temperature than the sourceof heat, i. e. the heating wall, and since the gases travel from thecenter towards the walls, they will take up a certain amount 01 heatfrom the wall. This retards the progress of heat to the core of thecharge. The gases will escape in a superheated condition to the. dome ofthe oven and to the tar main. The flow of gases takes place on a countercurrent principle, the gases being generated inside the coal charge atone temperature and flowing towards the source of heat-the heatingwallwith a zone of higher temperature. This is disadvantageous to theintended purpose of transferring the heat from the walls to the coalcharge. If one considers that the gases represent about 25% more orlessof the entire weight of the coal the retarding action these gasesexert upon the 'heat transfer must be large, and as a consequence thisalso prolongs the coking time. It also necessitates larger condensingsurfaces in the condenser of the by-product plant, to cool ofi thehigher temperatures due to the fact that the gases leave theoven in ahighly heated state. Moreover the resulting decomposition of the gasesresults in an endothermic reaction which absorbs heat from the heatinwall. Still another difficulty in the equa distribution of heat thru theheating walls is due to the taper. The width of the charge on the pusherside being smaller than on the opposite end of the oven, it will takeless time to finish that part of the charge with the result of producingan over or under carbonized coke product.

The irregularities which arise durin the distillation process by thebehavior 0% the charge in the high, narrow l y-product oven, areuncontrolable, and for this. reason the modern by-product oven fails toachieve its most important purpose, i. e. the distribution of t e heatin such a manner as to car'- 100 bonize'the coal char e uniformly. Theheat ap lication is far :Esom bein accurate.

The great significance of t e by-product oven as an industrial factorjustifies a-detailed explanation of the aforesaid defects, and will alsoassist in understanding my novel process of carbonizin coal, whicheliminates the described disa vantages.

My invention is illustrated in the accompanying drawings in which theillustrations show one or more ways for carrying the invention intoeifect.

Fig. 1 is a longitudinal section on line 1-1 of Fig. 2.

Fig. 2 is a vertical cross section on line DD of Fig. 1.

Fig. 3 is a vertical section and Fig. 4 is a horizontal section of amodification.

As shown best in Figs. 1 and 2, the heating floor or sole 1 of the ovenchamber, sealed from the admission of air, is of considerable width andcrowned by a low arch 2 which is rovided wth a number of charging holes3 or. filling the oven with the material to be coked. The charge to becoked or distilled is heated underneath and the heat supplied from bothends of the. charge. The charge consists of a flat, elongated,horizontal layer of coal which is longer than its breadth, thusproviding opposite ends for the layer at each end of the longitudinalaxis of the charge.

In the best embodiment of carrying out the method, short narrowlongitudinal, independent heating flames are provided, each extendingalong the sole of the oven and supplying coking heat at a temperaturesuiticient to coke the char e. The heat supply is subdivided both len twise and transversely of the layer. Lengt wise a plurality of parallel,equal heating zones are utilized and these are in turn subdivided intogroups by a transversedivision wall. The combustion flues 4, 5 aredivided by walls 6 forming channels 7, 8 which connect with waste gasmain 9, 10. Each combustion flue is provided with a gas supply nozzle 11which connects by pipe 12 with return gas main 13. Two series of gas suply nozzles are utilized, one for each oven ront. The air for supportingthe combustion is led to air chamber 14, 15, where it is exposed to theradiant heat of the waste mains 9, 10. An. aperture in the arc of theupper air'chamber' con-- nects by short vertical passages 16, in whichair shut-oil valve 16 is located, to air superheating channel 17, whichruns along underneath the combustion flues 4,. 5 thereby highlypreheating the air which escapes by a number of holes 18 impinging onthe gas from nozzles substantially at. right angles whereby an intimategas mixture and a complete combustion is produced, at a temperaturesuflicient to coke the coal. The oven is also equipped on both sideswith combustion flues 19, 20, which are provided also at both fronts ofthe oven with gas nozzles 21. These side combustion flues may or may notbe used, as desired. The air is supplied to the side flues in a similarmanner as for burning the gases in the sole flues.

Theside wall flues are low-their height is more or less determined bythe thickness of the coal layer which need not exceed 14 to 15 inches.It is obvious that in a sole coke oven havin a width as from 5 to 12feet, the heat rom the side walls cannot have any influence on the coallayer located in the middle of the oven; in fact the introduction ofheating the sides of the charge is in the main to prevent any losses ofheat from the sole flues which would occur, if the sole oven would haveno side wall heating flues.

On the other hand the temperature in the side walls need never to exceed900 to 1000 degrees centigrade and at times may be kept lower. In thesole combustion flues the temperature of the coking heat should not fallbelow 1250 degrees centi ade. It can be readily understood that if inthe side wall fines and in the sole flues located next to the side wallflues a temperatureof 1250 degrees centigrade is maintained, narrowstrips of coal runnin along the sides of the oven chamber, beingsubjected from two sides to the influence of heat, would be prematurelycarbonized, while the balance of coal would be still in process. Such anoccurrence is avoided by keeping the temperature in the side wallcombustion flues at about 900 to 1000 degrees centigrade. Each of theflues is supplied with gas and air. The regulating means 22, 23 areeasily accessible, and exposed to daylight.

By the division wall 6, which also helps to form the waste gas channels7, 8 for burned gases, the flue system is divided 'into two equalhalves, and as the oven is heated from both fronts the paths of travelfor the its combustible gas is very short. It also will be noticed thatthe entire area of the sole is subjected to the heat of combustiblegases, which is a considerable advantage over such methods, where theheat is applied to heating walls partly with combustible gases andpartlyv with gases from which the greater part of the heat has beenpreviously absorbed. The operation of the oven is as follows: After theoven is properly heated the covers 24 of the char ing holes are takenoff and the lorries moving on rails 25 discharge the coal into the oven.The doors 26 are then removed and the charge is leveled.

After leveling the charge the coal may be compressed by rolling cast'iron rollers over the charge, in order to obtain a more dense coal, ifso desired. The doors are re laced and luted so as to prevent theadmission of atmospheric air. The gas nozzles 11 and air valve 16" beingopened, combustion takes tion of the charge and noton the sides. The

formation of gaps parallel to the oven floor in Fig. 2 is impossible,for the weight of the charge (which weighs from 5 to 8 tons) will presssolidly upon the sole walls and the gases will escape in the directionindicated by arrows in Fig. 2.

The advantages of carbonizing the charge iniformly by my method will beapparent:

(1) The distillation gases are uniformly generated over all parts of theoven floor, due to the heating from both ends, and are conducted thruthe cooler zones of the charge, thereby avoiding decomposition of thegases.

(2) With the elimination of the gaps parallel to the oven floor, theheat conducin the high, narrow, chambers, the control and distributionof heat is more uniform and positive in my sole coke oven and by thebetter utilization of heat, the time for carbonization isreduced.

As previously stated, the charge of coal, subjected to my process, owingto its considerable width and to the comparatively shallow coal layer,may be compressed very eifectively, as by means of a movable rollerwhich is to be applied on the top of the charge for the production of adense coke.

What I claimed asv new and desire to secure by Letters Patent is:

1. The method of distilling a, flat, elongated, horizontal layer of coalwhich is thinner than its width and length, while the coal is in asealed oven chamber, which comprises subjecting the layer to coking heatfrom beneath from a plurality of parallel, longitudinal, independentlyregulable flames, air and gas for the flames being supplied fromopposite ends of the layer, and collecting the distillates so formed.

2. The method of carbonizing a flat, elon- .gated,'horizontal layer'ofcoal, while on the sole of a sealed oven chamber which comprisessupplying coking heat to the. layer from below at a temperaturesuflicient to coke'the coal by means of a plurality of independentflames, said flames originating at opposite ends of the layer, andextending along the sole of the oven.

3. The method of distilling coal while on the sole of a sealed ovenchamber which comprises spreading a charge of coal in an elongatedshallow layer, supplying coking heat, through the bottom and at bothends of the charge sufiicient to coke the coal simultaneously supplyingcoking heat through: both sides of the charge, and collecting thedistillate so formed.

4. The method of distilling coal while on the sole of a sealed ovenchamber which KLARA ZWILLINGER, Adwiaistmtrim of the Estate of BernhardZwz'lh'nger, deceased.

